Get/display the animation runtime fps in python
The last time I looked at this there was no way to directly get the value directly from a property of the API.

You can emulate it with a frame change handler, here is some test code that prints the approx fps to console.

import bpy
import time

t0 = -1
def timer(scene):
    global t0
    t1 = time.clock()
    fps = scene.render.fps  / scene.render.fps_base
    ms = 1000 * (t1 - t0)
    fps = min(fps, (1000 / ms))
    print("FPS:", fps)
    t0 = t1

bpy.app.handlers.frame_change_post.append(timer)